Caloric restriction-induced metabolic adaptation associated with amount of body weight lost – results from the LION study

Introduction: Metabolic adaptation is a disproportionate reduction in resting metabolic rate (RMR) during caloric restriction.

Methods: Data from the Lifestyle Intervention (LION) study (NCT04023942) were analyzed. RMR was measured by indirect calorimetry at baseline (V1), after an 8-week formula-based weight loss intervention (V2), after a 12-month weight maintenance intervention (V3), and after 12-month follow-up (V4). Metabolic adaptation was calculated by 1) estimating RMR by using an equation based on age, sex, fat mass, and fat-free mass, and 2) subtracting RMR_estimated from RMR_measured. Regression analysis examined the association between weight loss and change in metabolic adaptation from V1 to V2, adjusting for baseline variables.

Results: Data from 234 participants (age 46±11 years, BMI 34.3±2.8 kg/m², 69% women) were included. Participants lost 11.7±3.5 kg (V1–V2), gained 2.0±7.7 kg (V2–V3), and gained 4.0±6.0 kg (V3–V4). Metabolic adaptation was 0.0±130.0 kcal/day at V1, -70.9±109.9 kcal/day at V2, -1.2±130.0 kcal/day at V3, and 12.4±144.3 kcal/day at V4. Change in metabolic adaptation was associated with weight loss from V1 to V2 (β=.005, p=.003).

Conclusion: Caloric restriction induced metabolic adaptation, which was associated with the amount of weight lost.

Publication History

Article published online:
15 September 2025